<!DOCTYPE html>
<link rel=author href="mailto:jarhar@chromium.org">
<link rel=help href="https://bugs.chromium.org/p/chromium/issues/detail?id=1486750">
<link rel=help href="https://html.spec.whatwg.org/multipage/urls-and-fetching.html#document-base-url">
<link rel=help href="https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fallback-base-url">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<body>
<script>
test(() => {
  const doc1 = document.implementation.createHTMLDocument();
  assert_equals(doc1.baseURI, 'about:blank', 'document.implementation.createHTMLDocument()');

  const doc2 = document.implementation.createDocument('', '');
  assert_equals(doc2.baseURI, 'about:blank', 'document.implementation.createDocument("", "")');

  const doc3 = new Document();
  assert_equals(doc3.baseURI, 'about:blank', 'new Document()');
}, 'Synthetic documents should return about:blank for document.baseURI.');

test(() => {
  const doc = document.implementation.createHTMLDocument();
  assert_equals(doc.baseURI, 'about:blank', 'baseURI should be about:blank without a <base>.');

  const base = doc.createElement('base');
  base.href = '/foo';
  doc.head.appendChild(base);
  assert_equals(doc.baseURI, 'about:blank', '<base> with relative URL should not change the about:blank baseURI.');

  base.href = 'http://example.com/';
  assert_equals(doc.baseURI, 'http://example.com/', '<base> with complete URL should replace the about:blank baseURI.');
}, 'Synthetic documents should incorporate <base> href URLs correctly.');
</script>
